Renault's great starts

[hardingfv32]

1) Our discussion about starts has relevance to leaving after a pit stop.

2) All the teams have a system for accurately setting the grab point of the clutch. It probably makes its last evaluation of the clutch and starting spot track surface condition leaving for the parade lap. This provides a very consistent release curve for the driver controlled clutch paddle. It would be very easy for the teams to have a start simulator available at the track for the drivers to practice on. In the end the start is all in the drivers fingers. This is probably a well practiced activity.

3) Other than fuel economy and the throttle to pedal interface, what would be the advantage of changing the engine map? There is no reason to have a different map for low rpm's. The average lap does not see low rpm's. One map could have the correct optimization for both high and low rpm's.

In some conditions, such as rain, you might want to soften the engine output curve, but is that necessary for the start?

Brian

[Federico]

I'm pretty sure I saw in a video from ferrari where they explain all the buttons on their steering wheel there was one button for selecting a special engine map for the start and the first lap

[l4mbch0ps]

3) Other than fuel economy and the throttle to pedal interface, what would be the advantage of changing the engine map? There is no reason to have a different map for low rpm's. The average lap does not see low rpm's. One map could have the correct optimization for both high and low rpm's.

The advantage in changing the engine map doesn't come from shifting the power according to RPM, but rather by shifting the power according to gear ratio. As you work your way up the gears, you are effectively decreasing the torque at the wheels... even though torque at the crank may remain the same. This is one of the main reasons why it is easier to spin your tires in first gear than it is in fifth. The special maps allow the designers to provide the maximum USEABLE torque to the contact patch, without exceeding the traction limits.

That being said, it is true that a "start" map is used by most teams, and that map cannot be changed for a set period of time after the start, so we can safely say that they are not using gear based engine maps on the start.

[Richard]

OK I'll admit to being puzzled by the100kph limit on KERS. There is no written rule, but lots of refs to "can't". Here's a quote from Vettel in China:

SV: I did, but to be honest, my initial launch was not 100 per cent. I probably had problems to really start going, you feel that inside the car. It’s hard to wait then and I was probably a bit too aggressive later on. You can’t use KERS straight away, you have to wait until you reach 100kph, so I saw that I immediately lost a position to Jenson, which wasn’t nice and then Lewis behind.

scarbs said in a PM that it's a start thing, but unable to quote a rule or other ref.

[HampusA]

Maybe they have come up with some sort of launch control like the "ABS" they have on the rear wheels?

I´ve heard that since ABS is illegal, the teams tell the engine to give some more power either when the rears lock or just before so it´s impossible to lock the rears.
Truth or insanity?

[alelanza]

I´ve heard that since ABS is illegal, the teams tell the engine to give some more power either when the rears lock or just before so it´s impossible to lock the rears.
Truth or insanity?

They used to, but now it's illegal to do that as well. All the driver can do is set a fixed amount of engine braking while on overrun.

[HampusA]

Ok i see, i´m guessing he can do it "on the fly" ? incase of rain or whatever.

[alelanza]

That's correct, it's in one of several dial knobs in the steering wheel, needs to be used in conjunction with break balance and nowadays i would guess with kers harvest rate as well